The continuation of the study of the chemistry and metabolism of aromatic amino acids and amines is proposed. An investigation of the metabolism of DOPA will be pursued including the determination of and incorporation of radiolabeled DOPA into tissue protein. The toxicity of 2,4,5-trihydroxyphenylacetic acid formed from the transamination of DOPA and hydroxylation of 3,4-dihydroxyphenylpyruvate will be investigated. The extent to which the DOPA proceeds through this minor pathway will be estimated. Continuation of the study of reduced serotonin as a destructive inhibitor of serotonergic cells is proposed. BIBLIOGRAPHIC REFERENCES: Fellman, J.H., G.H. Wada, E.S. Roth. Metabolism and Properties of 3-Methoxy-4-Hydroxyphenylpyruvate; A metabolite of Dihydroxyphenylalanine. Biochem. Biophys. Acta, 381, 9 (1975). Fellman, J.H., Roth, E.S., Heriza, E.L., Fujita, T.S. Altered Pattern of Dopa Metabolism. Biochem. Pharm. (In Press).